Abstract Connections

Connections · 06:02 AM

snappychappy · 09-05-2012, 07:07 AM

Well thought out composition there, works very well.

**southlander** · 09-05-2012, 07:53 AM

I fell giddy just looking at this picture!

**Bob Harris** · 09-05-2012, 10:03 AM

Cool shot here Rob, reminds me of the old days. I don't think I could climb them anymore.

**eaglem** · 09-05-2012, 03:33 PM

Interesting perspective of a common object.

RobG · 09-05-2012, 03:49 PM

Originally posted by snappychappy

Well thought out composition there, works very well.

Thanks!

Originally posted by southlander

I fell giddy just looking at this picture!

Maybe think of it going horizontally instead of vertically?

Except then it would be like walking the plank... maybe not!

Originally posted by Bob Harris

Cool shot here Rob, reminds me of the old days. I don't think I could climb them anymore.

My hat off to you Bob, if you used to do electrical line work! I get worried enough with 240 volts, let alone the higher voltages in the distribution lines!

Originally posted by eaglem

Interesting perspective of a common object.

Thanks! I've been looking at ways to see what the DA 35 f2.8 limited produces in different circumstances. The bokeh at the bottom of this image is intriguing.

**Bob Harris** · 09-05-2012, 04:28 PM

Rob, you probably wouldn't of liked the 500,000 volt lines, a fluorescent bulb will light up from induction even though you are 50 foot away.

RobG · 09-05-2012, 08:13 PM

Originally posted by Bob Harris

Rob, you probably wouldn't of liked the 500,000 volt lines, a fluorescent bulb will light up from induction even though you are 50 foot away.

Nah, pass on that!

You remind me of a book I read about Nikola Tesla, who had an induction coil on the floor (I think) of his laboratory, and had lamps around the walls which were lit without wires. He did a lot of experiments with high frequency AC which don't seem to have been replicated since. Actually, I didn't know voltages that high were in use - I think the highest voltage transmission lines I've seen here are 60,000 volts. I also read that during some of Tesla's experiments in Colorado, horses miles away were electrocuted through their steel shoes!

sam-joseph · 09-05-2012, 08:25 PM

Ironically, you could have called this one "Goldmine", which refers to the exorbitant cost of electricity here now, thanks in large part to those politicians in Canberra where you took this shot.

Regards

**southlander** · 09-05-2012, 10:55 PM

RobG,

FYI, I think the supply into Canberra had been 132kV but upgraded in the last year or so to 330kV.

RobG · 09-06-2012, 02:24 AM

Originally posted by southlander

FYI, I think the supply into Canberra had been 132kV but upgraded in the last year or so to 330kV.

Which one?

I wonder if the US distribution voltages are higher than ours? The household supply is usually 120V @ 60Hz in the USA I think, while here it's 240V @ 50Hz, so I wonder whether the distribution voltages and currents are different.

**southlander** · 09-06-2012, 06:27 AM

I think you can get a pretty wide variety of voltages on the big transmission lines to suit the amount of power the utilities need to pump through and the length of the lines, and can even use DC transmission sometimes rather than AC (I think there is a new feeder running down the Hudson River into Manhattan that is DC with AC/DC converters at each end). Higher voltages equals a lot less power lost in heat radiated due to resistance in the cables. A lot of the smaller feeder between Australian towns I think are 132kV these days. You can appreciate why some of these bigger lines really crackle in drizzly/foggy weather! According to Wikipedia, the world's highest voltage transmission line is 1.15 MV (ie 1150kV) in Kazakhstan. Won't want to be too close to that if it flashed over!

The link below should take you to to a TransGrid pdf on works around the Canberra area. I don't know Canberra well, so I'll l;et you work out the areas they are talking about.

http://www.transgrid.com.au/projects/projects/ACTSupply/Documents/100505%20-...%20-%20Web.pdf

RobG · 09-06-2012, 05:08 PM

Originally posted by southlander

I think you can get a pretty wide variety of voltages on the big transmission lines to suit the amount of power the utilities need to pump through and the length of the lines, and can even use DC transmission sometimes rather than AC (I think there is a new feeder running down the Hudson River into Manhattan that is DC with AC/DC converters at each end). Higher voltages equals a lot less power lost in heat radiated due to resistance in the cables. A lot of the smaller feeder between Australian towns I think are 132kV these days. You can appreciate why some of these bigger lines really crackle in drizzly/foggy weather! According to Wikipedia, the world's highest voltage transmission line is 1.15 MV (ie 1150kV) in Kazakhstan. Won't want to be too close to that if it flashed over!

Thanks for the link! I understand the use of high voltages to minimise loss - I think Tesla wanted to use very high frequencies as well, but frequency conversion is a bit of a pain. Interesting that DC would be used, since Edison originally supplied DC into Manhattan, but it was poor for transmission over long distances. It's sad that Tesla gets so little recognition for the work he did inventing the AC generation and transmission system. I certainly wouldn't want to be anywhere near that megavolt line either!

Having said that - high voltages aren't the killer so much as high voltage compbined with high current. Static electricity off a car zaps you with a high voltage, but a very low current.

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09-05-2012, 07:07 AM	#2
snappychappy Veteran Member Join Date: Jun 2010 Location: Leeds Posts: 1,636	Well thought out composition there, works very well.

09-05-2012, 07:53 AM	#3
southlander Site Supporter Join Date: May 2012 Location: Adelaide Photos: Gallery \| Albums Posts: 1,364	I fell giddy just looking at this picture!

09-05-2012, 10:03 AM	#4
Bob Harris Site Supporter Join Date: Feb 2010 Location: Canon City, Colorado Photos: Gallery \| Albums Posts: 18,477	Cool shot here Rob, reminds me of the old days. I don't think I could climb them anymore.

09-05-2012, 03:33 PM	#5
eaglem Site Supporter Join Date: Feb 2009 Location: Perth Western Australia Photos: Gallery Posts: 43,162	Interesting perspective of a common object.

09-05-2012, 03:49 PM	#6
RobG Otis Memorial Pentaxian Join Date: Dec 2009 Location: Canberra Photos: Gallery \| Albums Posts: 8,905 Original Poster	Originally posted by snappychappy Well thought out composition there, works very well. Thanks! Originally posted by southlander I fell giddy just looking at this picture! Maybe think of it going horizontally instead of vertically? Except then it would be like walking the plank... maybe not! Originally posted by Bob Harris Cool shot here Rob, reminds me of the old days. I don't think I could climb them anymore. My hat off to you Bob, if you used to do electrical line work! I get worried enough with 240 volts, let alone the higher voltages in the distribution lines! Originally posted by eaglem Interesting perspective of a common object. Thanks! I've been looking at ways to see what the DA 35 f2.8 limited produces in different circumstances. The bokeh at the bottom of this image is intriguing.

09-05-2012, 04:28 PM	#7
Bob Harris Site Supporter Join Date: Feb 2010 Location: Canon City, Colorado Photos: Gallery \| Albums Posts: 18,477	Rob, you probably wouldn't of liked the 500,000 volt lines, a fluorescent bulb will light up from induction even though you are 50 foot away.

09-05-2012, 08:13 PM	#8
RobG Otis Memorial Pentaxian Join Date: Dec 2009 Location: Canberra Photos: Gallery \| Albums Posts: 8,905 Original Poster	Originally posted by Bob Harris Rob, you probably wouldn't of liked the 500,000 volt lines, a fluorescent bulb will light up from induction even though you are 50 foot away. Nah, pass on that! You remind me of a book I read about Nikola Tesla, who had an induction coil on the floor (I think) of his laboratory, and had lamps around the walls which were lit without wires. He did a lot of experiments with high frequency AC which don't seem to have been replicated since. Actually, I didn't know voltages that high were in use - I think the highest voltage transmission lines I've seen here are 60,000 volts. I also read that during some of Tesla's experiments in Colorado, horses miles away were electrocuted through their steel shoes!

09-05-2012, 08:25 PM	#9
sam-joseph Veteran Member Join Date: Oct 2009 Location: Newcastle, NSW, Australia Photos: Gallery Posts: 1,086	Ironically, you could have called this one "Goldmine", which refers to the exorbitant cost of electricity here now, thanks in large part to those politicians in Canberra where you took this shot. Regards

09-05-2012, 10:55 PM	#10
southlander Site Supporter Join Date: May 2012 Location: Adelaide Photos: Gallery \| Albums Posts: 1,364	RobG, FYI, I think the supply into Canberra had been 132kV but upgraded in the last year or so to 330kV.

09-06-2012, 02:24 AM	#11
RobG Otis Memorial Pentaxian Join Date: Dec 2009 Location: Canberra Photos: Gallery \| Albums Posts: 8,905 Original Poster	Originally posted by southlander FYI, I think the supply into Canberra had been 132kV but upgraded in the last year or so to 330kV. Which one? I wonder if the US distribution voltages are higher than ours? The household supply is usually 120V @ 60Hz in the USA I think, while here it's 240V @ 50Hz, so I wonder whether the distribution voltages and currents are different.

09-06-2012, 06:27 AM	#12
southlander Site Supporter Join Date: May 2012 Location: Adelaide Photos: Gallery \| Albums Posts: 1,364	I think you can get a pretty wide variety of voltages on the big transmission lines to suit the amount of power the utilities need to pump through and the length of the lines, and can even use DC transmission sometimes rather than AC (I think there is a new feeder running down the Hudson River into Manhattan that is DC with AC/DC converters at each end). Higher voltages equals a lot less power lost in heat radiated due to resistance in the cables. A lot of the smaller feeder between Australian towns I think are 132kV these days. You can appreciate why some of these bigger lines really crackle in drizzly/foggy weather! According to Wikipedia, the world's highest voltage transmission line is 1.15 MV (ie 1150kV) in Kazakhstan. Won't want to be too close to that if it flashed over! The link below should take you to to a TransGrid pdf on works around the Canberra area. I don't know Canberra well, so I'll l;et you work out the areas they are talking about. http://www.transgrid.com.au/projects/projects/ACTSupply/Documents/100505%20-...%20-%20Web.pdf

09-06-2012, 05:08 PM	#13
RobG Otis Memorial Pentaxian Join Date: Dec 2009 Location: Canberra Photos: Gallery \| Albums Posts: 8,905 Original Poster	Originally posted by southlander I think you can get a pretty wide variety of voltages on the big transmission lines to suit the amount of power the utilities need to pump through and the length of the lines, and can even use DC transmission sometimes rather than AC (I think there is a new feeder running down the Hudson River into Manhattan that is DC with AC/DC converters at each end). Higher voltages equals a lot less power lost in heat radiated due to resistance in the cables. A lot of the smaller feeder between Australian towns I think are 132kV these days. You can appreciate why some of these bigger lines really crackle in drizzly/foggy weather! According to Wikipedia, the world's highest voltage transmission line is 1.15 MV (ie 1150kV) in Kazakhstan. Won't want to be too close to that if it flashed over! Thanks for the link! I understand the use of high voltages to minimise loss - I think Tesla wanted to use very high frequencies as well, but frequency conversion is a bit of a pain. Interesting that DC would be used, since Edison originally supplied DC into Manhattan, but it was poor for transmission over long distances. It's sad that Tesla gets so little recognition for the work he did inventing the AC generation and transmission system. I certainly wouldn't want to be anywhere near that megavolt line either! Having said that - high voltages aren't the killer so much as high voltage compbined with high current. Static electricity off a car zaps you with a high voltage, but a very low current.